package acm.蓝桥4;

import java.util.Scanner;

public class 完全平方数 {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        long n=sc.nextLong();
        long l=sc.nextLong();
        long r=sc.nextLong();
        long res=0;
        for (long i = l; i <= r; i++) {
            if (!check(i)) {
                res++;
            }
        }
        System.out.println(res);
    }
    public static boolean check(long n) {
        if (n == 0) return false;
        double sqrt = Math.sqrt(n);
        return sqrt == (int) sqrt;
    }
}
